Specific Types of Encephalopathy

ENCEPHALOPATHY

Clinical Definition: While there are no official or specific textbook definitions, encephalopathy can be accurately described as a generalized alteration in all aspects of brain function (communication, memory, speech, orientation, behavior) due to a systemic underling cause that is usually reversible. It is typically acute (or subacute) in onset and resolves when the underlying cause is corrected.

Common causes of encephalopathy include fever, infection, dehydration, electrolyte imbalance, acidosis, organ failure, sepsis, hypoxia, drugs, poisons or toxins.

Toxic and Toxic-Metabolic encephalopathy (349.82) generally refers to the effects of drugs, toxins, poisons and medication; but physicians may use this term clinically to refer to encephalopathy caused by fever, sepsis, or other “toxic” conditions.

Metabolic (348.31) is intended to describe encephalopathy due to such things as fever, dehydration, electrolyte imbalance, acidosis, hypoxia, infection and organ failure.

Septic encephalopathy is a clinical term that expresses brain dysfunction as a manifestation of severe sepsis, and is also coded 348.31. Hepatic encephalopathy is coded as 572.2 (an MCC).

Untreated uremia causes encephalopathy before it progresses to uremic coma. Do not confuse with acute dialysis-associated encephalopathy which is classified as delirium.

The codes for Hypoxic Ischemic Encephalopathy (HIE) apply only to neonates.

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I-10: No significant changes. Toxic encephalopathy (G92), metabolic or septic (G93.41), encephalopathy, NEC (G93.49), or unspecified (G93.40).

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Recognition of encephalopathy is crucial for accurate documentation of the severity of illness of hospitalized patients. For many admissions, the principal reason for admission is actually the altered mental status due to underlying encephalopathy. In these cases, the encephalopathy can be coded as the PDX if it meets the definition of a principal diagnosis. For example, often patients are admitted with encephalopathy due to UTI.

As a co-morbid secondary diagnosis, the presence of encephalopathy of almost any type (toxic, septic, metabolic, uremic, hepatic, unspecified) qualifies as an MCC. Anoxic, alcoholic and hypertensive encephalopathy are CCs.

Delirium vs. Encephalopathy

Many physicians consider delirium and encephalopathy as essentially the same thing. However, from a coding perspective, delirium is classified as a mental disorder or as a symptom; encephalopathy is recognized as a specific neurologic diagnosis that identifies toxic and metabolic states affecting the brain.

For precise clinical documentation and correct coding, the diagnostic term encephalopathy is preferred for describing mental status alteration when due to toxic or metabolic causes. The term delirium is best reserved for psychiatric conditions unrelated to underlying systemic conditions.